Vibrator for loud speakers



y 3, 1932- F. SHIDA 1,856,791

VIBRATOR FOR LOUD SPEAKERS Filed April 8, 1931 2 Sheets-Sheet l Ihmentor May 3, 1932. F. SHIDA 1,856,791

VIBRATOR FOR LOUD SPEAKERS Filed April 8, 1931 2 Sheets-Sheet 2 3nnento1:

5am- ,JM

Gttorneg Patented May a. 1932 1,856,791

UNITED. STATES PATENT orricr.

I'UMIO BHIDA, OI KAWANISHI-GHO, KAWABE-GUN, HYOGO-KEN, In

. VIBBATOR FOB LOUD SYEAKEBB Application filed April 8, 1931, Serial no. 528,695, and in Japan January, 1931.

This invention relates to improvements in way of example one embodiment of the inthe construction of vibrators for loud speakvention, a ers. The object of the invention is to pro- Fig. 1 being a plan view of a vibrator of duce a light-weight vibrator which is able to the smooth surface type; resist the distorting effect of the electrical Fig. 2 a sectional elevation thereof on lme 5osound impulses and hence to reproduce clear, A-A of Fig. 1; undistorted sounds without materially 1n- Fig. 3 a plan view. of a vibrator of the corcreasing the weight of the vibrator. rugated type, and The essential requirements of a good vl- Ei .4 a sectional elevation thereof on line brator' for a loudspeaker are (1) the hght- A of Fig. 3. 65

ness in the weight and (2) the stifiness of The vibrator may be preparedasfollows 1- the vibrator in order to eifect the exact re- 1 First, wooden pattern for the cone, either production of the transmitted electrical soun corrugated oth, i re ared with radia waves into mechanical vibrations Wit out grooves corresponding to grooves of the distortion. In order to approximate these cone B. Then, an extremely thin and light 60 requirements, it has been the general practice sheet, 01'; Japanese paper is cut to the shape heretofore, to use a light and thin paper and and size exactly to fit and cover the segmenta other Suitable ma rlj s in h f rms of a areas from groove to groove, inclusive, as insemi-sphere, cone and other similar shapes of dicated at X in Figures 1 and 3. These segsmooth or corruagted surfaces. These conmental paper pieces are carefully and evenly 65 str tions, how ver, fall h r of the second pasted in layers on the pattern until the cone es ential requirement b V me,I i n A acquires sufficient strength. Inasmuch as the the result therefore, ,thev ncur the -d1sadedges of the adjacent segmental pieces overvantage 0 being liable to undesirable i lap at each oove,the thickness at the grooves t1ons. Because of these distortions the is twice that of the intermediate parts. In 70 sounds produced by the loud Speak rs this way a substantial reinforcement of the equipped with such vibrators lack the desired grooves is efiected, resulting in great y melearneSS an naturalnesscreased strength to thecone without mate- According to, the present invention, this rially increasing the weight ofthe cone itsel difl' culty 1s overcome by pr i mg severe For this reason, the conical vibrator made iiiappropriate and balanced stiffening mem r accordance with this invention as describe referably comprising radlal grooves P above has the characteristics of producing ]ect1ng ridges-on the surface of the vibrator, clear, natural and undistorted sound vibrathe latter being made of paper, cloth or other tions. i suitable materials of either smooth or corin the accompanying. claims, the term rugated type. When the vibrator is-made of ridges is to be understood in a comprehenseveral phes of thm paper, cloth, or other .sive senseas embracing grooves, ribs, corrusultable materials, the sheets are so cut a d, gations or other equivalent reinforcements or put together as to overlap each other at each stifiened portions. 40 groove or projecting ridge,thus making those What is claimed is: 85 portions doubly stifi and obviating the tend- 1. A vibrator for a loud speaker provided ency towards undesirable distortions withwith reinforced radial ridges. out material increase to the weight of the 2. A vibrator for a loud speaker formed vibrator. j of a web of light material having radial v The accompanying drawings illustrate by ridges, said materialbeing of greater thic'kness in the line of said rid es than elsewhere.

. vibrator for :1 Ion speaker, provided with' radial ridges, said vibrator being made rom segmental pieces which overlap at Said 4. A vibrator for a loud speaker provided with radial reinforcing ridges, said vibrator ing formed of several plies of suitable light materials, the several plies comprising segmental pleces which overlap at the said ridges. 

